Two-way Heteroscedastic ANOVA when the Number of Levels is Large Short Running Title: Two-way ANOVA
نویسندگان
چکیده
We consider testing the main treatment effects and interaction effects in crossed two-way layout when one factor or both factors have large number of levels. Random errors are allowed to be nonnormal and heteroscedastic. In heteroscedastic case, we propose new test statistics. The asymptotic distributions of our test statistics are derived under both the null hypothesis and local alternatives. The sample size per treatment combination can either be fixed or tend to infinity. Numerical simulations indicate that the proposed procedures have good power properties and maintain approximately the nominal α-level with small sample sizes. A real data set from a study evaluating forty varieties of winter wheat in a large-scale agricultural trial is analyzed.
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